Researchers investigate heat- and light-emitting walls

Walls that emit heat and light are among the ideas that researchers at a Welsh sustainable building centre are investigating for possible mass-production.

The Sustainable Product Engineering Centre for Innovative Functional Industrial Coatings (SPECIFIC) consortium led by Tata Steel Europe and Swansea University is planning to demonstrate a range of wall coatings that can capture, store and release energy before selecting three for testing on a pilot production line next year.

The project aims to develop steel and glass products that can be used to retrofit buildings to reduce their net energy usage and builds on the group’s research into solar electricity-generating wall coatings.

One of the technologies under development is a heat-emitting wall coating made from a polymer containing particles that heat up due to electrical resistance when a current is passed through the material.

The temperature can be controlled by adjusting the current. Spreading the coating across a wall would mean each section of coating could be kept at a safe temperature to touch while sufficiently heating the room.

‘The trick is designing panels that heat up uniformly,’ Prof Dave Worsley, SPECIFIC’s research director, told The Engineer. ‘We’ve got all the particles in the right place in the lab and we’ve got to do the same for a larger panel.’

This could be particularly useful in parts of a building where it is difficult or uneconomical to fit other heating infrastructure such as plumbing, added industrial director Paul Jones.

Feasibility

The centre has begun inviting industry experts to examine this technology and others it is developing, such as light-emitting polymer coatings, to give their views on which would be most suitable for large-scale production and commercialisation.

‘We need to do a lot of work to make sure that this is technology people would want to scale up,’ said Worsley.

The team plan to experiment with manufacturing the materials using a process described as ‘between printing and coating’ on a modular pilot line that can be adjusted to produce the different substances.

These will then be trialled at the Sustainable Building Envelope Centre (SBEC), Tata’s existing research showcase at its plant in Shotton, north Wales, unveiled in March this year as a collaboration with the Low Carbon Research Institute (LCRI).

Retrofitting

SBEC is housed in a former industrial building retrofitted with a range of technologies such as transpired solar collectors (TSCS) that capture and warm ambient air and use it to heat the building.

‘It’s very important to look at existing buildings because they account for around 50 per cent of UK carbon emissions, so just looking at new buildings won’t solve the problem,’ said Jones.

‘There are around 4bn sqm of existing UK roofs and walls that are suitable for retrofitting, and Tata makes around 100m sqm of material a year,’ added Worsley.

Batteries

Current plans for energy storage at the centre involve using large stand-alone batteries, but future work by the researchers could even look at the idea of building batteries into the walls themselves.

‘We have the flexibility to work with the whole building and ask what we can do with it,’ said technology transfer fellow Dr Trystan Watson. ‘We can think differently from other battery users.

‘We’re really excited about what we can do with what’s only kept the rain out so far. But it also has to fit into high-volume manufacturing.’

Jones stressed that this kind of technology was at least 10 years away.

SPECIFIC was established in April 2011 as one of the UK’s six Innovation and Knowledge Centres of research excellence.

It is funded by £20m from the main partners, £9.5m from the Technology Strategy Board and Engineering & Physical Sciences Research Council, and contributions from the Welsh government.

ICI Nobel Division produced prototype silicone rubber coatings loaded with carbon with the aim of using such coatings as heating panels in the 60's and early 70's.I was involved in testing one of these panels in a heated car seat.It worked very well (12 volt) The main thrust of the development was for incorporation in buildings eg in ceiling panels.I haven't seen or heard of the development since!